Re: SDW plenary agenda item - Namespace for SOSA and SSN ontology

Dear all,

I am also having problems to understand the one-namespace proposal from the wiki description.

If I take a term that is in both ontologies (e.g., I can see Sensor in both sosa.ttl and ssn.ttl, with different properties), where does http://www.w3.org/ns/unify/TermInBothOntologies take me, the SOSA or the SSN ontology? I assume SOSA as the "core". So, both ontologies would define a unify:TermInBothOntologies. If I look at the SSN ontology I would "see" a different unify:TermInBothOntologies than I see when looking at the SOSA ontology or when de-referencing the unify:TermInBothOntologies URI (which redirects to the SOSA ontology).

If my understanding is correct, shouldn’t there be a constraint that the SSN ontology includes the SOSA definitions plus additional ones (at least for the SOSA terms that are included in SSN)?

Is this approach common practice and will this be understood?

Best regards,
Clemens



On 22 Feb 2017, at 03:39, Armin Haller <armin.haller@anu.edu.au<mailto:armin.haller@anu.edu.au>> wrote:

Krzysztof, thanks for pointing that out! That was indeed a mistake, it should have read sosa:Platform and ssn:System. There is no sosa:System in our current proposal. But tomorrow it is all about the vote on the mechanics of the namespace for SOSA and SSN.

On 22/2/17, 11:27 am, "Krzysztof Janowicz" <janowicz@ucsb.edu<mailto:janowicz@ucsb.edu>> wrote:

   Just to avoid confusion. Armin is talking about ssn:System, not
   sosa:System (which does not exist). The concept that does exist in SOSA
   is sosa:Platform.


   On 02/21/2017 03:56 PM, Armin Haller wrote:
Hi Raphaël,

Thanks for your comment! In fact, the wiki is so detailed on the mechanics is because we *only* want to vote on the mechanics of the namespace issue tomorrow. The classes/properties that are shown are only exemplative. We have separate issues around the Platform and System class (i.e. https://www.w3.org/2015/spatial/wiki/Platform). In fact, there is a sosa:System and all current proposals under consideration in the Platform/System issue do retain a sosa:System class in the core. Please do ignore the modelling of those classes for tomorrow’s vote.

Once we have come to a decision on the *mechanics* on how to deal with namespaces we can tackle the remaining issues with the architecture of the integration (see also https://www.w3.org/2015/spatial/wiki/Proposals_for_rewriting_SSN), i.e. essentially a decision on *reuse of classes/properties only in SSN* or *equivalence/subclass/-property relationships in SSN to SOSA classes/ property*.

Cheers,
Armin

On 22/2/17, 10:24 am, "Raphaël Troncy" <raphael.troncy@eurecom.fr<mailto:raphael.troncy@eurecom.fr>> wrote:

    Dear Armin, all,

If you have an opinion on this, please do have a close look at the two
options on our Wiki page that outline the implementation implications of
each option: https://www.w3.org/2015/spatial/wiki/NamespaceIssue


    I think that the two options are insufficiently described in order to
    make an informed decision (sections 3.1 and 3.2). There is a lot of text
    explaining the mechanics of content negotiation which is sort of obvious
    for anyone who is familiar with the linked data concepts. On the
    contrary, there is insufficient information on the bulk of the issue,
    i.e. what (concepts and properties) is defined where, what is re-used,
    what is being further defined with more axioms between SOSA and (new) SSN.

    In the current option 1, one can only see the definition of a
    sosa:Platform in the sosa namespace, while this concept is further
    axiomatized in ssn.ttl using the concept of ssn:System. Does this mean
    that there is no sosa:System?

    I wish that the wiki page was not distracted by all the mechanics of
    trivial content negotiation and linked data terms dereferencing, and
    instead, focus on what is defined where precisely and exhaustively.
    Best regards.

       Raphaël

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    Raphaël Troncy
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   Krzysztof Janowicz

   Geography Department, University of California, Santa Barbara
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